Lasers are currently used in numerous applications in which it is necessary to control the laser beam. A laser head in which the beam is deflected by reflection from two mirrors controlled by two galvanometers is commonly used for marking supports such as plastic or metals. Galvanometers are known means for controlling the rotation angle of the mirrors, wherein (electro)magnets within the galvanometers are brought in rotational movements. Each mirror is made to rotate in a controlled way about its own axis by the corresponding galvanometer, and the two axes are in general orthogonal positioned with respect to each other. In this way, the outgoing beam can be deflected according to a system of coordinates and its path can be controlled to obtain the required working. The present invention is related to similar devices in which two separate mirrors are able to deflect a laser beam in order to obtain all possible positions within an X-Y coordinate plane. The invention is in particular related to such a single device able to control the angle rotation of said mirror in a precise manner.
Another prior known method and device for the control of the angle rotational movement of these deflecting mirrors is the use of a plurality of electromagnets whereby elastic forces balance the magnetic forces acting upon a mirror.
In the present text ‘angle rotation’ means any rotational movement over an angular reach, which angular reach may be positive or negative and being in general smaller than 180°.
Other applications of these devices are for example in the medical field whereby for various treatments use is made of a laser beam controlled by means of a pair of galvanometers to execute a scanning movement.
The currently known deflection systems controlled by corresponding galvanometers are complicated, cumbersome and inaccurate. Furthermore their reaction time is long and becomes unacceptable. Another problem is the high impedance of the existing angle rotation devices, due to the high number of current wires within the electromagnets, which are needed to provide a reasonable strong magnetic field.
The purpose of the present invention is to provide an alternative for the commonly used galvanometers, such that the present invention provides a laser beam deflection device which is more compact and accurate and easy to fabricate and which permits a more precise and a more rapid manipulation of the laser beam. Another object is to provide an angle rotating device having a low impedance and as a result thereof provides for a more accurate and faster reaction time for the rotational movement.